Ha! I was literally in the midst of sending through a patch for
this. Thanks for also taking a look and beating me to it!
This LGTM, feel free to add:
Reviewed-by: Matt Bobrowski <mattbobrowski@xxxxxxxxxx>
On Wed, Mar 08, 2023 at 11:37:13AM +0100, Roberto Sassu wrote:
> From: Roberto Sassu <roberto.sassu@xxxxxxxxxx>
>
> Commit 62622dab0a28 ("ima: return IMA digest value only when IMA_COLLECTED
> flag is set") caused bpf_ima_inode_hash() to refuse to give non-fresh
> digests. IMA test #3 assumed the old behavior, that bpf_ima_inode_hash()
> still returned also non-fresh digests.
>
> Correct the test by accepting both cases. If the samples returned are 1,
> assume that the commit above is applied and that the returned digest is
> fresh. If the samples returned are 2, assume that the commit above is not
> applied, and check both the non-fresh and fresh digest.
>
> Fixes: 62622dab0a28 ("ima: return IMA digest value only when IMA_COLLECTED flag is set")
> Reported by: David Vernet <void@xxxxxxxxxxxxx>
> Signed-off-by: Roberto Sassu <roberto.sassu@xxxxxxxxxx>
> ---
> .../selftests/bpf/prog_tests/test_ima.c | 29 ++++++++++++++-----
> 1 file changed, 21 insertions(+), 8 deletions(-)
>
> diff --git a/tools/testing/selftests/bpf/prog_tests/test_ima.c b/tools/testing/selftests/bpf/prog_tests/test_ima.c
> index b13feceb38f..810b14981c2 100644
> --- a/tools/testing/selftests/bpf/prog_tests/test_ima.c
> +++ b/tools/testing/selftests/bpf/prog_tests/test_ima.c
> @@ -70,7 +70,7 @@ void test_test_ima(void)
> u64 bin_true_sample;
> char cmd[256];
>
> - int err, duration = 0;
> + int err, duration = 0, fresh_digest_idx = 0;
> struct ima *skel = NULL;
>
> skel = ima__open_and_load();
> @@ -129,7 +129,15 @@ void test_test_ima(void)
> /*
> * Test #3
> * - Goal: confirm that bpf_ima_inode_hash() returns a non-fresh digest
> - * - Expected result: 2 samples (/bin/true: non-fresh, fresh)
> + * - Expected result:
> + * 1 sample (/bin/true: fresh) if commit 62622dab0a28 applied
> + * 2 samples (/bin/true: non-fresh, fresh) if commit 62622dab0a28 is
> + * not applied
> + *
> + * If commit 62622dab0a28 ("ima: return IMA digest value only when
> + * IMA_COLLECTED flag is set") is applied, bpf_ima_inode_hash() refuses
> + * to give a non-fresh digest, hence the correct result is 1 instead of
> + * 2.
> */
> test_init(skel->bss);
>
> @@ -144,13 +152,18 @@ void test_test_ima(void)
> goto close_clean;
>
> err = ring_buffer__consume(ringbuf);
> - ASSERT_EQ(err, 2, "num_samples_or_err");
> - ASSERT_NEQ(ima_hash_from_bpf[0], 0, "ima_hash");
> - ASSERT_NEQ(ima_hash_from_bpf[1], 0, "ima_hash");
> - ASSERT_EQ(ima_hash_from_bpf[0], bin_true_sample, "sample_equal_or_err");
> + ASSERT_GE(err, 1, "num_samples_or_err");
> + if (err == 2) {
> + ASSERT_NEQ(ima_hash_from_bpf[0], 0, "ima_hash");
> + ASSERT_EQ(ima_hash_from_bpf[0], bin_true_sample,
> + "sample_equal_or_err");
> + fresh_digest_idx = 1;
> + }
> +
> + ASSERT_NEQ(ima_hash_from_bpf[fresh_digest_idx], 0, "ima_hash");
> /* IMA refreshed the digest. */
> - ASSERT_NEQ(ima_hash_from_bpf[1], bin_true_sample,
> - "sample_different_or_err");
> + ASSERT_NEQ(ima_hash_from_bpf[fresh_digest_idx], bin_true_sample,
> + "sample_equal_or_err");
>
> /*
> * Test #4
> --
> 2.25.1
>
/M
